This application claims benefit of Japanese Patent Application No. 2001-312611 filed on Oct. 10, 2001, the contents of which are incorporated by the reference.
The present invention relates to waveguide type optical device used as filter device in such fields as optical communication and data processing using light and also to method of manufacturing the same. More specifically, the present invention relates to a waveguide type optical device permitting improvement of the yield in manufacture and also to method for manufacturing the same.
With spread of optical communication techniques and development of data processing techniques using light, optical waveguide elements have become in wide spread use as optical waveguide filters. Such optical waveguide elements permitting various functions by utilizing interference of light generally vary in refractive index and optical path length in dependence on the ambient temperature. Therefore, the pass bandwidth and center wavelength fluctuate with individual manufactured optical waveguide elements.
Accordingly, the center wavelength of optical waveguide elements including AWG (arrayed waveguides) is adjusted by using a Velch element or heater as a temperature controller such as to satisfy grid specifications prescribed in ITU (International Telecommunication Unison). For example, in a quartz system optical waveguide element, the center wavelength has a temperature dependency of about 0.1 nm/° C., and adjustment to a desired center wavelength is made by adjusting the preset temperature of a waveguide type optical device using such an optical waveguide element.
However, the center wavelength of manufactured optical waveguide elements or waveguide type devices incorporating such elements may not always be preset to a desired value in a temperature range adjusted by the above temperature controller. The optical waveguide elements and waveguide type optical devices, which are incapable of being temperature adjusted with the temperature controller, have heretofore become rejected products, and this has been a significant cause of the fact that the yield of manufactured elements or devices can not be improved.